Rotary toothbrush with lip guard



y 1953 D. P. GROVER 2,644,973

ROTARY TOOTHBRUSH WITH LIP GUARD Filed Ndv. 3, 1950 IIHII W-/ IHII" Patented July 14, 1953 UNITED STATES PATENT "OFFICE ROTARY TOOTHBRUSH WITH LIP GUARD Donald P. Grover, Chicago, Ill. Application November 3, 1950, Serial No. 193,843 r 1 This invention relates in general to rotary toothbrushes of the type particularly adapted for personal use as distinguished from those commonly used by dentists, and, more especially to a novel form of lip guard to prevent the lip and fleshy portions of the mouth of a user from being injured by the bristles of the rotating brush. The forms of lip guard disclosed herein are further variations over those disclosed in my copending applications, Serial No. 691,273 filed August 17, 1946 now Patent No. 2,533,106 issued December 5, 1950, SerialNo. 691,979 filed August 21,1946, now Patent No. 2,533,107 issuedDecember 5, 1950 and Serial No. 692,270, filed 'August 22, 1946, now Patent No. 2,533,108 issued De cember 5,1950.

Various forms of power driven rotary toothbrushes have beendeveloped heretofore. but have found very little favor with the public in general. One of the disadvantages of the early type of rotary toothbrush was the absence of any shield partially surrounding the brush element; thus causing some of the toothpaste on the brush to be thrown off-and splattered about during the rotation of the brush and permitting the brush to contact the soft inner portions of the mouth causing irritation thereof. v

A later development introduced a shield which extended lengthwise of and partially surrounded the rotating brush element to prevent such splattering and mouth irritation. However, actual-usage of this type of brush proved unsatisfactory because of the tendency of the lip of the user to be drawn inwardly against the bristles of the brush and between the bristles and the edge of the shield when the brush was placed against the teeth. I have been able to overcome the disadvantages of theseearlier types of rotary toothbrushes'in my present invention, the principal 'object of which is to provide a power driven rotary toothbrush having novel guard means to prevent the lip of the user from being pulled or drawn be tween the bristles of the brush element and shiel during rotation thereof. H

Another object of the invention is to provide a rotary toothbrush having a plurality of spaced guards along the length of the brush element and extending between the bristles thereon whereby'the lip or fleshy mouth-parts of the user is prevented from being pulled or-drawn between the brush and shield or guard support during rotation thereof. A further object is to provide arotary tooth brushhaving a shield. extending lengthwise of 7 Claims. (01. 15-23) and partially surrounding the brush element, wherein a plurality of thin guard members are spaced along the length of the shield and extend inwardly between bristles of the brush element from the upper edge of the shield to prevent the lip or fleshy mouth parts of a'user from being drawn between the shield and brush element during rotation thereof.

' Still another and more specific object of the invention is to provide a rotary toothbrush wherein guard'members are provided having the entire portions thereof located below the plane of the brush spindle to enable the brush to be removed for replacement or cleaning purposes without disturbing the guard members.

Still another specific object of the invention is to provide" a rotary toothbrush having a shield extending longitudinally of and partially surrounding the brush element wherein a lip guard in the form of relatively thin partitions extend between the sides of the shield and are spaced along the length of the shield and wherein the upper edge of each partition is substantially flat andextends below the brush spindle.

A further specific object of the invention is to provide a rotary toothbrush wherein elongated guard supporting members extend outwardly from one end of the handle and along opposite sides of the brush element and wherein relatively thin bars or rods extend transversely between said guard members and below the brush spindle.

Still another specific object of the invention is to provide a further modified form of rotary toothbrush wherein an elongated member forming the lip guard extends longitudinally of the brush element on opposite sides thereofand spaced inwardly from the upper longitudinal edge gt a shield fixed to one end of the handle por- Other objects and advantages of the invention will become apparent upon a reading ofthe following description taken in conjunction with the accompanying drawing in which:

Fig. 1 is a perspective view of a rotary toothbrush embodying one form of the present inven- Fig. 2 is-an enlarged vertical sectional view taken substantially along the plane of line 2-2 of Fig. 1;

Fig. 3 a fragmentary perspective view of a rotary toothbrush embodying a modified form '01 lip guard;

Fig. 4 is a vertical sectional view taken substantiallyalong the plane of line 4-4 of Fig. 3;

Fig. is a fragmentary perspective view of a rotary toothbrush illustrating a still further modified form of lip guard; and

Fig. 6 is a vertical sectional view taken substantially along the plane of line 66 of Fig. 5.

Briefly described, the invention herein consists primarily in the provision of guard means against which the lip of the user of the rotary toothbrush will ordinarily bear and be directed by rotation of the brush during the use thereof thereby to guide the lip away from the brush bristles and prevent injury thereto. When the rotary brush is in use and placed against the teeth, the brush element is preferably designed to rotate in a manner to brush the teeth away from the gums, this procedure being considered by dentists as the proper way to brush teeth.

It has been found in actual practice that when no lip guards are present, brushes of this character heretofore known have had a tendency to ina itiate and lacerate the lip and fleshy portions of the mouth. If a shield is present, the tendency is then to pull these soft portions of the mouth between the edge of the shield and the bristles on the rotating brush. Serious injury to the lip may result, but if not, at least the experience is decidedly unsatisfactory and unpleasant, thereby discouraging further use of the toothbrush because of the resulting rawness and bleeding of the lip. This has been considered the principal reason for the lack of commercial success of earlier rotary toothbrushes. As stated previously, numerous specific forms of guard means may be designed to accomplish the same purpose, three such forms of the invention being disclosed herein.

Referring now more particularly to the drawing, and, especially to that form of the invention shown in Figs. 1 and 2, ther is illustrated a rotary toothbrush having a handle portion I. This handle portion may obviously assume any desired shape and size, but is preferably formed so as to be conveniently held in the hand and should be formed of a plastic, or other suitable non-conducting material. The handle portion may, if desired, embody its own electric motor, or other form of actuating mechanism, or it may be driven from an external source such as a flexible shaft connected to a source of power.

The type of brush and handle portion disclosed herein is particularly adapted for use in connection with a flexible shaft drive and for that reason the handle I may be provided with a suitable shaft rotatably mounted therein, all as clearly shown and described in my above referred to co-pending applications.

In the preferred form of the invention, the handle portion I terminates in a shield member 2 in the form of an arcuate shell adapted to cover one side of the rotating brush and terminates in an upwardly extending end portion 3. The end portion 3 has an inner surface spaced from a substantially parallel and flat surface 4 at the end of the handle itself. The shaft 5 which is suitably mounted for rotation within the handle portion I is provided at its outer end with suitable connecting means such as a transversely extending slot 6 adapted to receive a corresponding rib on the end of a brush spindle I. The spindle I has been only partially shown in Fig. 1 and the outline of the bristles of the brush element are indicated by the dot-dash line 8 in order that the construction of the lip guard may be more clearly seen.

The guard members for preventing injury to the lip in this form of the invention constitute a plurality of solid thin partitions each spaced along the length of the shield 2 and having a substantially flat upper edge III passing below the brush spindle I. These partitions 9 are spaced apart a sufficient distance to permit the bristles of the brush to pass therebetween during the rotation thereof. In the absence of these guard members 9 the rotating brush would have a tendency to come against the lip or fleshy portions of the mouth of a user and draw these portions downwardly between the upper longitudinal edge of the shield 2 and the bristles of the brush. When this is permitted to occur, injury to the lip and fleshy portions will result. The guard members 9, however, due to the upper edges thereof which extend inwardly from the upper edges of the shield, will prevent this drawing inwardly of the lip and will tend to guide the lip down along the outer side of the shield, thereby protecting it from injury.

The distance the guard members or partitions 9 should be spaced apart does not become critical until the spacement is too great. If these partitions are spaced apart a distance to permit a portion of the lip to be drawn inwardly between the shield and the rotating brush, then the guard members serve no useful purpose. It has been determined in actual practice that the maximum distance which these partitions can be spaced apart and still function effectively as a lip guard is about 1% inch. From the standpoint of effectiveness of the lip guard there is no limit as to how close these partitions may be placed. On the other hand, consideration must be given to the fact that the bristles of the brush must pass between these partitions, as clearly seen by the dot-dash outline of the brush in Fig. 2. In this connection it has been determined that the preferable lower limit of the spacement should be approximately inch. This form of the invention, while similar in many respects to some of the forms disclosed in my co-pending applications above referred to, nevertheless, embody certain differences and particularly the substantially straight upper edge of the partitions. It has been found, however, that this form of the invention is equally as effective as many of the other forms referred to herein.

The form of the invention shown in Figs. 3 and 4 also embodies a rotary toothbrush having a handle portion I I terminating in a relatively flat face I2 at one end thereof. As before, the handle portion may contain a shaft mounted therein for rotation and to which may be connected the brush spindle I3. In this modified form, the shield has been omitted and the upper longitudinal edges of the shield of Fig. 1 which support the guard members have been replaced by the elongated guard supporting members I4. These members are preferably, although not necessarily, substantially parallel with each other and are substantially parallel with the brush spindle. These elongated members I4 are provided one on each side of the brush spindle I3 and may be secured in any suitable way to the face I2 of handle II or may be formed integrally therewith, as desired.

The outer terminal ends of the guard supporting members I4 support a disc I5 having an opening I6 therein adapted to'receive the outer end of the brush spindle I3 whereby the brushelement may be properly mounted for rotation. A plu rality of guard members I! extend transversely between the guard supporting members I4 and are spaced along the length thereof in the same manner described above with respect to the partitions 9 in Fig. 1. These guard members I! preferably pass below brush spindle l3, thereby to enable the brush to be removed for replacement or cleaning purposes .without disturbing the guard members. Inasmuch asthe bars l1 function in the same manner as the upperedges of the partitions 9, it will be evident that the effectiveness thereof toprevent injury to the lip of a user will be substantially the same as the eifectivenessof the form of the invention shown in Fig. 1.

Referring now to Figs. 5 and 6, here again the rotary toothbrush comprises a handle portion [8 similar to that described above with respect to Fig.1. The handle l8 terminates in a shield portion I 9 having an outer upturned end member 20 provided with-an opening 2|. The shield I9 is arcuate in crosssection and permits rotation of the brush element therein while also being effective to prevent splattering of toothpaste. The handle l8 may again be'provided with a shaft rotatably mounted therein and adapted to have connected thereto the brush spindle 22. The outer end of spindle 22 may be rotatably mounted in opening 2 I. a

The lip guard in this form of the invention comprises an elongated bar or rod 23 at each side of the handle portion spaced inwardly from the upper longitudinal edge of the shield l9 and extending lengthwise of the brush spindle 22. Viewing Figs. 5 and 6, it will be seen that each end of each bar 23 is supported by the outwardly extending end members 24 which are, in turn, secured to the ends of shield 19. It will be evident, however, that these guard members 23 may be secured and supported in proper position in any other desired, or suitable manner.

The bars or guard members 23 are spaced inwardly from the upper edges of shield IS a relatively short distance so that only the outermost edges of the brush will contact these bars. It is necessary, however, that these bars extend inwardly a suflicient distance to perform their necessary function. If they extend longitudinally of the brush element but were spaced outwardly therefrom, then the bristles of the brush would tend to draw the lip between the lip guard and the brush and would thereupon serve no useful purpose.

Viewing Fig. 6, it will be evident that during rotation of the brush element, if there is a tendency to draw the lip inwardly this tendency will cease as soon as the lip reaches one of the guard members 23, thereupon effectively preventing any injury.

From the foregoing description it will be apparent that the present device embodies certain novel forms of lip guards for use in connection with rotary toothbrushes, all of which will effectively prevent injury to the lip and fleshy portions of the mouth of a user. As stated previously, the brush is intended to be used in such a way that rotation of the brush element is away from the gums. If the toothbrush is constructed so that the brush element always rotates in the same direction, then the lip guard in any case may be located on only one side thereof. Thus, the lip guards disclosed herein may be dispensed with along one side of the brush element without departing in any way from the spirit of the invention. The provision of lip guards along both sides of the rotating brush element maybe necessary, however, if suitable mechanism is provided to reverse the direction of rotation of the brush.

The expression below the brush spindle when used'herein relative to the location-citric guard members, it is to be understood gthat thezposition of thetoothbrush body will be such that the closed side of the shield faces downwardly. In this connection it will be noted that a. common feature of all forms of the invention herein is that a horizontal plane through the axisof :the brush spindle when the closed side of the shield faces downwardly will be parallel tothe upper edge, or surface of the guard members. Changes may be made in the form, construction and arrangement of parts from those dis-.- closed herein without in any way departingfrom the'spirit of the invention or sacrificing any of the attendant advantages thereof, provided, how? ever, .that such changes. fall within the scope ,0 the claims appended hereto; a ,The invention is-hereby claimed as follows: ,1 l. A rotary toothbrush of. the class described, comprising a handle portion having a, rotatable shaft extending therethrough, guard supp rting means having edge portions extending longitudinally of said handle portion and extending for: wardly from one end thereof and located onop'e posite sidesof a vertical plane passing through said handle portion, a spindle supporting member fixed to the outer ends of said guard sup: porting means, one end of said shaftandsaid spindle supporting means being adapted .toro-, tatably support a spindle having bristles thereon forming a brush: element, and, lip. guard means extending in a straight line inwardly from the edge portions of said guard supporting means and in a common plane below said brush spindle. 2. A rotary toothbrush of the class described. comprising a handle portion having a rotatable shaft extending therethrough, a shield having an arcuate form and extending forwardly from one end of said handle portion and terminati in upwardly facing spaced longitudinal edge portions, a brush element connected to one 'end of said shaft and rotatable therewith, said shield partially surrounding said brush element, and lip guard means on said shield extending inwardly from the longitudinal edge portions thereof, the upper surfaces of said lip guard means at opposite sides of said shield lying in a common plane, whereby the lip or fleshy mouth parts of a user will be prevented from being drawn between the longitudinal edges of said shield and the rotating brush element.

3. A rotary toothbrush of the class described. comprising a handle portion having a rotatable shaft extending therethrough, a brush element connected to one end of said shaft and rotatable therewith, guard supporting means fixed to said handle portion and having edge portions extending longitudinally of said brush element on opposite sides of said shaft, and lip guard means including a plurality of spaced members extending transversely between the edge portions of said guard supporting means, the upper surfaces of said members lying in a plane located below the axis of said shaft, whereby the lip or fleshy mouth parts of a user will be prevented from being drawn against the bristles of said brush element.

4. A rotary toothbrush of the class described, comprising a handle portion having a rotatable shaft extending therethrough, a brush element connected to one end of said shaft and rotatable therewith, a shield extending lengthwise of and partially surrounding said brush element, and a plurality of spaced partitions extending transversely of said shield between the bristles on said brush element, the upper edges of said partitions being substantially flat and all lying in a common plane located below the axis of said shaft, whereby the lip or fleshy mouth parts of a user will :be prevented from being drawnbetween said shield and the bristles of said rotating brush element.

' 5. A rotary toothbrush of the class described, comprising a handle portion having a rotatable shaft extending therethrough, a brush element connected to one end of said shaft and rotatable therewith, lip guard supporting means extending lengthwise of said brush element and located on opposite sides of the axis thereof, and lip guard means including a plurality of spaced bars extending between said lip guard supporting means, all located in a common plane located below the axis of said shaft, whereby the lip or fleshy mouth parts'of a user will be prevented from being drawn against the bristles of the rotating brush element.

1 6. A rotary toothbrush of the class described, comprising a handle portion having a rotatable shaft extending therethrough, a brush element connected to one end of said shaft and rotatable therewith, a shield extending lengthwise of and partially surrounding said brush element, said shield terminating on opposite sides of the brush element in upwardly facing longitudinal edges, and lip guard means including an elongated bar spaced inwardly from and substantially parallel with at least one of said longitudinal edge por- 8 tions of the shield, whereby the lip or fleshy mouth parts of a user will be prevented from being drawn between said shield and the bristles of the rotating brush element.

7. A rotary toothbrush of the class described, comprising a handle portion having a rotatable shaft extending therethrough, a brush element connected to one end of said shaft and rotatable therewith, a shield extending lengthwise of and partially surrounding said brush element, said shield terminating on opposite sides of the brush element in upwardly facing longitudinal edges, and lip guard means including an elongated bar spaced inwardly from and substantially parallel with said longitudinal edges of said shield, said bars being located in a common plane positioned below the axis of said shaft, whereby the lip or fleshy mouth parts of a user will be prevented from being drawn between said shield and the bristles of the rotating brush element.

DONALD P. GROVER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,430,967 Fendrich Oct. 3, 1922 1,578,495 Zave Mar. 30, 1926 2,533,108 Grover Dec. 5, 1950 FOREIGN PATENTS Number Country Date 676,771 France Feb. 27, 1930 

